Manufacture of vermiculite bonded material



I06. COMPOSITIONS, Lxanuum COATING OR PLASTIC.

UNITED STATES PATENT OFFICE MANUFACTURE OF W BONDED James Keeth, Spokane, Wash., assignor to Universal Insulation Company, Chicago, 111., a corporation of Illinois No Drawing. Application May 4, 1932, Serial No. 609,269

12 Claims.

My present invention relates to an improved plastic composition of W as a mineral base, and a fiber as a ler, w ch composition is adapted for use in plastic form as originally prepared, or the prepared composition may be dehydrated for storage or shipment and afterwards hydrated for immediate use.

Jefierisite in its natural state is mined in the form of brownish colored sheets, or books, of various sizes, and these foliated structures are comparatively light in weight in proportion to their size. When the natural mineral is exfoliated, by baking or roasting in an oven, the material is not only dehydrated, but a given weight of the mineral is increased in size and decreased in weight. After exfoliation and dehydration, the mineral still preserves its leaf formation with a lighter color, but the leaves are so light in weight and so fragile that the material may be crushed or pulverized between the fingers of the hand. I avail myself of this capacity of the exfoliated mineral for further exfoliation or pulverizing, by grinding the exfoliated mineral, with water, in a grinding or pulverizing mill of suitable type.

Thus, in carrying out my invention, I place the foliated mineral in an oven or furnace where it is subjected t t a proper temperature for a suitable pen, mineral is and a given size of the mineral is expane several times its original volume or size. The mineral, by heating, is thus v gxfoiiated and comes out of the heating process 0 mp or lumps of various sizes and shapes,

and in a fiuffy condition. The material is thus ex- 85 panded into clumps, lumps, books, leaves, flakes, and other forms, and in this condition, I subject the material to grinding in a suitable mill, where the above enumera ed forms are transformed into minute flakes, leaves, or scale-like particles.

This grinding of the dehydrated and exfoliated material must be accomplished in the presence of water which is added to the mill in suitable quantities to form a plastic mass. The fine grinding of the mineral in the presence of water forms a plastic pulp or paste that is adhesive and homogeneous, and this plastic pulp may be worked into a great variety of shapes or forms for industrial and other purposes appropriate for plasters. The grinding of the exfoliated mineral in water thus provides and produces a self-binding plaster or plastic pulp base material,

The fibrous filler for the composition is obtained by macerating vegetable fiber, such as and other wood fiber cane straw marsh grass. 56 1g inexpensive ma erials, into a fi nely com:

then be added to the mineral pulp to increase the 5 volume without materially adding to its weight and must be thoroughly united therewith.

It is my practice to perform the operation of preparing my composition by grinding the mineral and filler pulp together and in a single operation by placing approximately two parts of mineral with one part of fiber in a suitable mill or grinder and adding water from time to time until the pulp mass is thoroughly ground and is of extreme" fineness and has the consistency required for application.

This grinding in the presence of water is highly essential as it is only through this process that the binding qualities of the mineral material become useful and are mixed in the general mass 20 so that no outside binder or other ingredient is necessary to form a plaster or covering.

The proportions of the mix may be altered to meet the case or particular need but the general proportions are about two of mineral matter to one of fiber pulp. This composition effects a homogeneous plaster having a wide variety of uses and which has sound proofing insulation and fire-proofing qualities of exceptional merit. Too much emphasis can not be placed upon the fact that the grinding of the mineral matter must take place in the presence of water and the grinding operations shall be continued in such a nature that an extreme fineness of material is provided in a paste form combined with the mineral pulp either when ground together or separately and thereafter brought together.

In my experimenting so far I have found that only burr stones have been entirely suitable for my work. Through the use of a burr type grinder, such as was used for the grinding of flour, I have been enabled to get that extreme fineness and mixture of the water so highly essential in my process.

If the composition is not desired for lmmediate use, the moisture is expressed therefrom to lighten its weight for shipping purposes, or for convenient storage purposes, and after the composition has been dehydrated in suitable manner the mass is broken up into small particles, before it sets, and is then ready for storing or shipping. When this material is to be used, water is added thereto to render it plastic.

The plastic composition thus produced may be troweled against either wood or metal laths, to

form a plaster wall that clings or adheres to its support, and when dry or set, the wall is sound proof and fireproof, and light in weight. A building wail thus constructed is free from cracks or other defects, and the face of the wall, while plastic, may be troweled to a compact and smooth finish.

The plastic composition may also be employed as a covering and insulation for hot-water and steam pipes, and it may be either plastered on the pipes, or molded into shapes, which when set and dry, may be applied to the pipes in customary manner.

The completed structures made up from the composition, are extremely light in weight, yet

strong and durable; they possess considerable 'a plastic composition, dehydrating the plastic composition, and then hydrating the last mentioned material preparatory to use.

2. The process which consists in exfoliating Jefierisite, mixing the exfoliated material with a vegetable fiber and comminuting these together in the presence of water to form a self-binding plastic composition and then dehydrating the plastic composition for storage or shipment purposes.

3. The process which comprises grinding a heat expanded vermiculite with water until it is sumciently reduced in size to act as a binder, and

drying the product.

4. A coherent mass in which the binding material is solely a comminuted exfoliated mineral of the vermiculite group.

5. A coherent mass composed of a filler bound together at least in substantial part by an ex- 5 foliated mineral of the vermiculite group sufliciently reduced in size to act as a binder for said filler.

6. A coherent mass composed of a filler bound together at least in substantial part by an ex- 10 foliated mineral of the vermiculite group reduced to sufiiciently thin flakes to act as a binder for said filler.

7. As a binding material a comminuted exfoliated mineral of the vermiculite group. 15 8. A substantially dry body of flakes of an exfoliated mineral of the vermiculite group sufficiently thin to have the properties of a binder when moist.

9. A substantially dry body of an exfoliated l0 mineral of the vermiculite group of sufiiciently small size to have the properties of a binder when moist.

10. The process of forming a coherent mass comprising reducing an exfoliated mineral of the 25 vermiculite group to sufliciently fine form to act as a binder, mixing the same with filler material and water, and drying the mixture.

11. The process of forming a coherent mass comprising reducing an exfoliated mineral of the vermiculite group to sufficiently thin flake form to act as a binder, mixing the same with a filler material and water, and drying the mixture.

12. The process of grinding an exfoliated mineral of the vermiculite group with water until it is sufficiently reduced in size to act as a binder, and drying the product.

JAMES KEETH. 

